1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * vmx_set_nested_state_test
4 *
5 * Copyright (C) 2019, Google LLC.
6 *
7 * This test verifies the integrity of calling the ioctl KVM_SET_NESTED_STATE.
8 */
9
10 #include "test_util.h"
11 #include "kvm_util.h"
12 #include "processor.h"
13 #include "vmx.h"
14
15 #include <errno.h>
16 #include <linux/kvm.h>
17 #include <string.h>
18 #include <sys/ioctl.h>
19 #include <unistd.h>
20
21 /*
22 * Mirror of VMCS12_REVISION in arch/x86/kvm/vmx/vmcs12.h. If that value
23 * changes this should be updated.
24 */
25 #define VMCS12_REVISION 0x11e57ed0
26 #define VCPU_ID 5
27
28 bool have_evmcs;
29
test_nested_state(struct kvm_vm * vm,struct kvm_nested_state * state)30 void test_nested_state(struct kvm_vm *vm, struct kvm_nested_state *state)
31 {
32 vcpu_nested_state_set(vm, VCPU_ID, state, false);
33 }
34
test_nested_state_expect_errno(struct kvm_vm * vm,struct kvm_nested_state * state,int expected_errno)35 void test_nested_state_expect_errno(struct kvm_vm *vm,
36 struct kvm_nested_state *state,
37 int expected_errno)
38 {
39 int rv;
40
41 rv = vcpu_nested_state_set(vm, VCPU_ID, state, true);
42 TEST_ASSERT(rv == -1 && errno == expected_errno,
43 "Expected %s (%d) from vcpu_nested_state_set but got rv: %i errno: %s (%d)",
44 strerror(expected_errno), expected_errno, rv, strerror(errno),
45 errno);
46 }
47
test_nested_state_expect_einval(struct kvm_vm * vm,struct kvm_nested_state * state)48 void test_nested_state_expect_einval(struct kvm_vm *vm,
49 struct kvm_nested_state *state)
50 {
51 test_nested_state_expect_errno(vm, state, EINVAL);
52 }
53
test_nested_state_expect_efault(struct kvm_vm * vm,struct kvm_nested_state * state)54 void test_nested_state_expect_efault(struct kvm_vm *vm,
55 struct kvm_nested_state *state)
56 {
57 test_nested_state_expect_errno(vm, state, EFAULT);
58 }
59
set_revision_id_for_vmcs12(struct kvm_nested_state * state,u32 vmcs12_revision)60 void set_revision_id_for_vmcs12(struct kvm_nested_state *state,
61 u32 vmcs12_revision)
62 {
63 /* Set revision_id in vmcs12 to vmcs12_revision. */
64 memcpy(&state->data, &vmcs12_revision, sizeof(u32));
65 }
66
set_default_state(struct kvm_nested_state * state)67 void set_default_state(struct kvm_nested_state *state)
68 {
69 memset(state, 0, sizeof(*state));
70 state->flags = KVM_STATE_NESTED_RUN_PENDING |
71 KVM_STATE_NESTED_GUEST_MODE;
72 state->format = 0;
73 state->size = sizeof(*state);
74 }
75
set_default_vmx_state(struct kvm_nested_state * state,int size)76 void set_default_vmx_state(struct kvm_nested_state *state, int size)
77 {
78 memset(state, 0, size);
79 if (have_evmcs)
80 state->flags = KVM_STATE_NESTED_EVMCS;
81 state->format = 0;
82 state->size = size;
83 state->hdr.vmx.vmxon_pa = 0x1000;
84 state->hdr.vmx.vmcs12_pa = 0x2000;
85 state->hdr.vmx.smm.flags = 0;
86 set_revision_id_for_vmcs12(state, VMCS12_REVISION);
87 }
88
test_vmx_nested_state(struct kvm_vm * vm)89 void test_vmx_nested_state(struct kvm_vm *vm)
90 {
91 /* Add a page for VMCS12. */
92 const int state_sz = sizeof(struct kvm_nested_state) + getpagesize();
93 struct kvm_nested_state *state =
94 (struct kvm_nested_state *)malloc(state_sz);
95
96 /* The format must be set to 0. 0 for VMX, 1 for SVM. */
97 set_default_vmx_state(state, state_sz);
98 state->format = 1;
99 test_nested_state_expect_einval(vm, state);
100
101 /*
102 * We cannot virtualize anything if the guest does not have VMX
103 * enabled.
104 */
105 set_default_vmx_state(state, state_sz);
106 test_nested_state_expect_einval(vm, state);
107
108 /*
109 * We cannot virtualize anything if the guest does not have VMX
110 * enabled. We expect KVM_SET_NESTED_STATE to return 0 if vmxon_pa
111 * is set to -1ull, but the flags must be zero.
112 */
113 set_default_vmx_state(state, state_sz);
114 state->hdr.vmx.vmxon_pa = -1ull;
115 test_nested_state_expect_einval(vm, state);
116
117 state->hdr.vmx.vmcs12_pa = -1ull;
118 state->flags = KVM_STATE_NESTED_EVMCS;
119 test_nested_state_expect_einval(vm, state);
120
121 state->flags = 0;
122 test_nested_state(vm, state);
123
124 /* Enable VMX in the guest CPUID. */
125 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
126
127 /*
128 * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without
129 * setting the nested state but flags other than eVMCS must be clear.
130 * The eVMCS flag can be set if the enlightened VMCS capability has
131 * been enabled.
132 */
133 set_default_vmx_state(state, state_sz);
134 state->hdr.vmx.vmxon_pa = -1ull;
135 state->hdr.vmx.vmcs12_pa = -1ull;
136 test_nested_state_expect_einval(vm, state);
137
138 state->flags &= KVM_STATE_NESTED_EVMCS;
139 if (have_evmcs) {
140 test_nested_state_expect_einval(vm, state);
141 vcpu_enable_evmcs(vm, VCPU_ID);
142 }
143 test_nested_state(vm, state);
144
145 /* It is invalid to have vmxon_pa == -1ull and SMM flags non-zero. */
146 state->hdr.vmx.smm.flags = 1;
147 test_nested_state_expect_einval(vm, state);
148
149 /* Invalid flags are rejected. */
150 set_default_vmx_state(state, state_sz);
151 state->hdr.vmx.flags = ~0;
152 test_nested_state_expect_einval(vm, state);
153
154 /* It is invalid to have vmxon_pa == -1ull and vmcs_pa != -1ull. */
155 set_default_vmx_state(state, state_sz);
156 state->hdr.vmx.vmxon_pa = -1ull;
157 state->flags = 0;
158 test_nested_state_expect_einval(vm, state);
159
160 /* It is invalid to have vmxon_pa set to a non-page aligned address. */
161 set_default_vmx_state(state, state_sz);
162 state->hdr.vmx.vmxon_pa = 1;
163 test_nested_state_expect_einval(vm, state);
164
165 /*
166 * It is invalid to have KVM_STATE_NESTED_SMM_GUEST_MODE and
167 * KVM_STATE_NESTED_GUEST_MODE set together.
168 */
169 set_default_vmx_state(state, state_sz);
170 state->flags = KVM_STATE_NESTED_GUEST_MODE |
171 KVM_STATE_NESTED_RUN_PENDING;
172 state->hdr.vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
173 test_nested_state_expect_einval(vm, state);
174
175 /*
176 * It is invalid to have any of the SMM flags set besides:
177 * KVM_STATE_NESTED_SMM_GUEST_MODE
178 * KVM_STATE_NESTED_SMM_VMXON
179 */
180 set_default_vmx_state(state, state_sz);
181 state->hdr.vmx.smm.flags = ~(KVM_STATE_NESTED_SMM_GUEST_MODE |
182 KVM_STATE_NESTED_SMM_VMXON);
183 test_nested_state_expect_einval(vm, state);
184
185 /* Outside SMM, SMM flags must be zero. */
186 set_default_vmx_state(state, state_sz);
187 state->flags = 0;
188 state->hdr.vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
189 test_nested_state_expect_einval(vm, state);
190
191 /*
192 * Size must be large enough to fit kvm_nested_state and vmcs12
193 * if VMCS12 physical address is set
194 */
195 set_default_vmx_state(state, state_sz);
196 state->size = sizeof(*state);
197 state->flags = 0;
198 test_nested_state_expect_einval(vm, state);
199
200 set_default_vmx_state(state, state_sz);
201 state->size = sizeof(*state);
202 state->flags = 0;
203 state->hdr.vmx.vmcs12_pa = -1;
204 test_nested_state(vm, state);
205
206 /*
207 * KVM_SET_NESTED_STATE succeeds with invalid VMCS
208 * contents but L2 not running.
209 */
210 set_default_vmx_state(state, state_sz);
211 state->flags = 0;
212 test_nested_state(vm, state);
213
214 /* Invalid flags are rejected, even if no VMCS loaded. */
215 set_default_vmx_state(state, state_sz);
216 state->size = sizeof(*state);
217 state->flags = 0;
218 state->hdr.vmx.vmcs12_pa = -1;
219 state->hdr.vmx.flags = ~0;
220 test_nested_state_expect_einval(vm, state);
221
222 /* vmxon_pa cannot be the same address as vmcs_pa. */
223 set_default_vmx_state(state, state_sz);
224 state->hdr.vmx.vmxon_pa = 0;
225 state->hdr.vmx.vmcs12_pa = 0;
226 test_nested_state_expect_einval(vm, state);
227
228 /*
229 * Test that if we leave nesting the state reflects that when we get
230 * it again.
231 */
232 set_default_vmx_state(state, state_sz);
233 state->hdr.vmx.vmxon_pa = -1ull;
234 state->hdr.vmx.vmcs12_pa = -1ull;
235 state->flags = 0;
236 test_nested_state(vm, state);
237 vcpu_nested_state_get(vm, VCPU_ID, state);
238 TEST_ASSERT(state->size >= sizeof(*state) && state->size <= state_sz,
239 "Size must be between %ld and %d. The size returned was %d.",
240 sizeof(*state), state_sz, state->size);
241 TEST_ASSERT(state->hdr.vmx.vmxon_pa == -1ull, "vmxon_pa must be -1ull.");
242 TEST_ASSERT(state->hdr.vmx.vmcs12_pa == -1ull, "vmcs_pa must be -1ull.");
243
244 free(state);
245 }
246
disable_vmx(struct kvm_vm * vm)247 void disable_vmx(struct kvm_vm *vm)
248 {
249 struct kvm_cpuid2 *cpuid = kvm_get_supported_cpuid();
250 int i;
251
252 for (i = 0; i < cpuid->nent; ++i)
253 if (cpuid->entries[i].function == 1 &&
254 cpuid->entries[i].index == 0)
255 break;
256 TEST_ASSERT(i != cpuid->nent, "CPUID function 1 not found");
257
258 cpuid->entries[i].ecx &= ~CPUID_VMX;
259 vcpu_set_cpuid(vm, VCPU_ID, cpuid);
260 cpuid->entries[i].ecx |= CPUID_VMX;
261 }
262
main(int argc,char * argv[])263 int main(int argc, char *argv[])
264 {
265 struct kvm_vm *vm;
266 struct kvm_nested_state state;
267
268 have_evmcs = kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS);
269
270 if (!kvm_check_cap(KVM_CAP_NESTED_STATE)) {
271 print_skip("KVM_CAP_NESTED_STATE not available");
272 exit(KSFT_SKIP);
273 }
274
275 /*
276 * AMD currently does not implement set_nested_state, so for now we
277 * just early out.
278 */
279 nested_vmx_check_supported();
280
281 vm = vm_create_default(VCPU_ID, 0, 0);
282
283 /*
284 * First run tests with VMX disabled to check error handling.
285 */
286 disable_vmx(vm);
287
288 /* Passing a NULL kvm_nested_state causes a EFAULT. */
289 test_nested_state_expect_efault(vm, NULL);
290
291 /* 'size' cannot be smaller than sizeof(kvm_nested_state). */
292 set_default_state(&state);
293 state.size = 0;
294 test_nested_state_expect_einval(vm, &state);
295
296 /*
297 * Setting the flags 0xf fails the flags check. The only flags that
298 * can be used are:
299 * KVM_STATE_NESTED_GUEST_MODE
300 * KVM_STATE_NESTED_RUN_PENDING
301 * KVM_STATE_NESTED_EVMCS
302 */
303 set_default_state(&state);
304 state.flags = 0xf;
305 test_nested_state_expect_einval(vm, &state);
306
307 /*
308 * If KVM_STATE_NESTED_RUN_PENDING is set then
309 * KVM_STATE_NESTED_GUEST_MODE has to be set as well.
310 */
311 set_default_state(&state);
312 state.flags = KVM_STATE_NESTED_RUN_PENDING;
313 test_nested_state_expect_einval(vm, &state);
314
315 test_vmx_nested_state(vm);
316
317 kvm_vm_free(vm);
318 return 0;
319 }
320